Abstract: Methods and apparatus for processing a substrate are provided herein. In some embodiments, a method for processing a substrate includes: directing a stream of material from a PVD source toward a surface of a substrate at a non-perpendicular angle to the plane of the surface to selectively deposit the material on a top portion of one or more features on the substrate and form an overhang extending beyond a first sidewall of the one or more features; and etching a first layer of the substrate beneath the one or more features selective to the deposited material.

Abstract: The present disclosure relates to novel methods and apparatuses for generating hydrogen sulfide or hydrogen selenide gas from decomposition of a solid precursor. In some embodiments, the generated gas is cooled so as to condense a by-product of the decomposition and thereby increasing the purity of the gas. In some embodiments, the generated hydrogen sulfide or hydrogen selenide gas is used to prepare metal sulfide or metal selenide films.